250 likes | 762 Views
The International Search of Deeply Bound Kaonic States. Laura Fabbietti. S. Wycech, Nucl Phys. A450 (1986) 399c. Underlaying Theory Experimental Results and some Interpretations New Experiments. T.Yamazaki and Y. Akaishi, PLB (2002 ). MeV =50 MeV. Im f. Kaon. p. p.
E N D
The International Search of Deeply Bound Kaonic States Laura Fabbietti S. Wycech, Nucl Phys. A450 (1986) 399c Underlaying Theory Experimental Results and some Interpretations New Experiments
T.Yamazaki and Y. Akaishi, PLB (2002) MeV =50 MeV Im f Kaon p p 10 MeV BE, M=1420 MeV/c2 M=1390 MeV/c2, 50 MeV p p Later.. Dote and W. Weise hyp2006 Proc., nucl-th/0701050 N.V. Shevchenko et al., Phys. Rev. Lett. 98, 082301 (2007) MeV =100 MeV The (1405) Case Assumption: L(1405) -> T=0, K-N state Bare KN potential that reproduces: K-N scattering lengths Binding energies and width of kaonic atom Binding Energy and Width of L(1405) How many poles? Weise et al. arXiv:nucl-th:0712.1612 Can we measure (1405)?
Experimental Searches for KC • Missing-mass spectroscopy • Example: • Invariant-mass spectroscopy • Example: • (stopped K, N) reaction • KEK E471/E549 • 4He(K-stop, n)S+(3140) ppnK-? (BE=169MeV) • 4He(K-stop, p)S0(3115) ppnK-? (BE=193MeV) • FINUDA/DAFNE • Li/C(K-stop, +p)ppK- • (K,N) reaction • BNL-AGS E930 • 16O(K-,n)15OK- • Al+Al, Ni+Ni - FOPI (p,d) • p+4He - Obelix (d)
Experimental result E471@ KEK 4He(stopped K-, n)ppnK-
ppnK- pnnK- Iwasaki et al. nucl-ex/0310018 T. Suzuki et al. Phys. Lett B 597, 263 (2004) Observed BK ~ 173 MeV GK ~ 25 MeV M ~ 3137 MeV/c2 Predicted(Akaishi 2002) BKth ~127 MeV including the relativistic correction GKth~ 30 MeV BKexp - BKth ~ 46 MeV Observed BK ~ 194 MeV GK ~ 21 MeV M ~ 3117 MeV/c2 M. Sato et al nucl-ex/0708.2968v1
K-Li ppK p FINUDA @ DAΦNE e+-e- collider -> f ->K+ K- Energy Resolution for L : 1 MeV (FWHM)
ppK- in p and back-to-back correlations Agnello et al. PRL 94(2005)212303
Proton Spectra with FINUDA Agnello et alNucl.Phys.A775:35-50,2006 Momentum distribution for protons 6Li 12C P->275 MeV/c P->275 MeV/c + cos p Impact parameter from Montecarlo from Experimental Data (6Li) K-+d-->-+p -->n+p With d at rest. But... np have 250 MeV/c --> p cannnot be monoenergetic!!! proton pion Yamazaki et al. nucl-ex/0609041v2
Finuda d for 6Li -target M. Agnello et al.Phys.Lett.B654:80-86,2007. Ld – invariant mass analysis M = 3251 ± 6 MeV G = 37 ± 14 MeV Y = (4.4 ± 1.4) . 10-3 / stopped K- Statistical significance: 3.9 No structure visible for 12C – target! (claim: FSI destroys signal)
Another (ppnK-) – claim OBELIX – Experiment at LEAR T. Bressani et al. Nucl.Phys.A789:222-242,2007. Significance: 2.6 (3.1) s Peak: 3190 ± 15 MeV Width: G < 60 MeV (Ld) invariant mass
Ni+Ni Al+Al FINUDA Search for ppK- in HIC (FOPI) Rapidity distribution Lp – invariant mass FINUDA midrapidity Excess observed in Ni+Ni and Al+Al with statistical significance of ~ 5. Yield located in spectator/fireball interface region (like non-strange clusters). Peak position in variance with FINUDA result. Interpretation unclear: SN – FSI, bound state (H1+), partial inv. mass of heavier state (e.g. 4LHe).
Summary for Strange Di/Tri-baryons d (ppnK-) p (ppK-)
Results from the DEAR Experiment (Kaonic hydrogen) Courtesy of W.Weise K-p Scattering Length • Inhaltsfolie
Scattering Data & Kaonic Atoms L(1405) cannot be described using Chiral Perturbation Theory. Chiral SU(3) dynamics with Coupled channels (KN<->Sp) Scattering data
‚Data Base‘ for the Effective Potentials Need for ‚Yes‘ or ‚No‘ experiment for the ppK- system (FOPI..) Need for high statistics Kaonic Atom Data (SIDDHARTA) Need for an accurate measurement of the Sp channel (FOPI..)
I. Zychor et al nucl-exp/0705.1039v2 p+p(Ep=2.8 GeV/c)-->pK+Y0 (1385)-->but NO (1405)--> FWHM()=5 MeV/c2 (1405) @ANKE Phase space background L= 70 pb-1 Disto : Tot((1405)@ 2.83 GeV =12 b extrapolated @ 3.5 GeV = 40 b
p+p 'L(1405)‘+p+K+ ppK-+K+ L+p S+p p- + p L+g+p Missing Mass & Invariant Mass p+p ‚L(1405)‘+p+K+ +p+K+ 0 n+- p0- 4 charge particles + evt hyp. ppK- production in p+p reactions T. Yamazaki et T. Akahishi, nucl-th/0604049 (2006) L* L(1405) p+p: short range interaction (r<0.3fm) R(L*-p)~1.45 fm assisted by a large momentum transfer
CDC Helitron PLAWA siΛVio A siΛVio B Barrel/RPC FOPI Setup First Level Trigger (Ch. Mul) + trigger CDC siΛVio B p- p p silicon Vertexing and identification online siΛVio A L Trigger: Online Vergleich zwischen Multiplizität siΛVio A und Multiplizität siΛVio B. p K+ 3 cm 10 cm
t d p K+ p+ p- K- K+ and identification Data from p+C@ 3.5GeV Courtesy of N. Herrmann Sep07 Ni+Ni@1.94AGeV P (GeV/c) v (cm/ns) K+ - identification by momentum – TOF analysis up to plab=1GeV/c Time resolution estimate from fast pions: st(RPC)<80ps L: Sig = 194 S/B = 3.7 FWHM= 11 MeV P = 4.6*10-4
Expected Signal for ppK Direct K+PID 27°<qK+<45°, 0<pK+<1GeV/c p+pL+K++p Indirect K+ PID (evt hypothesis) 7°<qK+<33° S/(S+B) = 0.03 for s= 5 S=1000 (s(ppK-)=1mb) Needed beam time (5s) =72 shift Granted beam time in Apr07 = 42 shifts +12 p.s.
First Hint in HADES Apr07 p+p@3.5GeV, 1/75 of the total statistics: 75.000 L-K+ events.
E=3.5 GeV E=3GeV 4.0 M2KL (GeV2) 3.5 3.0 2.5 4.5 5.0 5.5 6.0 6.5 M2pL (GeV2) Comparison HADES vs FOPI Thanks to the MDC De/dx Number calculated for 42 shifts and a beam intensity of 105 p/sec ( including extraction time and duty cycle)
KLOE & AMADEUS KLOE --> AMADEUS Cryogenic target Inner Tracker Kaon trigger
Analysis of the KLOE Data For the kaonic clusters a total luminosity of L=3.5/4 fb-1 is needed. Luminosity upgrade @ Dane
Future Measurement and Analysis New Data FINUDA@DANE (K-,N) HADES@GSI (p,p) New Experiments FOPI@GSI (p,p) 2009 HADES@GSI (p,N) E15@J-PARC (K-,N) 2009 AMADEUS @DANE (K-,N) 2010 FAIR..... What about theory? Need for Calculations of FSI pK+ Interpretation of the FOPI p excess in Al+Al and Ni+Ni ..........LEANNIS Network proposal at FP7 for this particular issue....